냉매 충전량의 조건 변화에 따른 냉동시스템의 성능 분석

양형석(Hyeong-Seok Yang) 산업기술교육훈련학회 2014 산업기술연구논문지 (JITR) Vol.19 No.2

This study is the performance variation analysis of refrigeration systems by changing the amount of refrigerant charging quantity according to adjusting the refrigerant charging 600gram, 800gram, and 1,000gram with vapor compressional refrigeration training equipment. At 600g refrigerant charging, the superheat, outlet temperature of compressor, refrigeration effect, coefficient of performance, refrigeration capacity were higher than 1,000gram refrigerant charging, while at 1,000gram refrigerant charging, evaporating and condensing pressure, compression work, were higher than 800gram refrigerant charging condition, Thus, we could see changes of the refrigeration system performance s factor the affect of amount of between resonable refrigerant charging and over charging conditions.

뉴럴 네트워크 알고리즘을 이용한 비드 가시화

구창대,양형석,김중영,신상호,Koo, Chang-Dae,Yang, Hyeong-Seok,Kim, Jung-Yeong,Shin, Sang-Ho 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.5

In this paper, we propose the Tangible Virtual Reality Representation Method to using haptic device and feature to morphology of created bead from Flux Cored Arc Welding. The virtual reality was started to rising for reduce to consumable materials and welding training risk. And, we will expected maximize virtual reality from virtual welding training. In this paper proposed method is get the database to changing the input factor such as work angle, travelling angle, speed, CTWD. And, it is visualization to bead from extract to optimal morphological feature information to using the Neural Network algorithm. The database was building without error to extract data from automatic robot welder. Also, the Neural Network algorithm was set a dataset of the highest accuracy from verification process in many times. The bead was created in virtual reality from extract to morphological feature information. We were implementation to final shape of bead and overlapped in process by time to using bead generation algorithm and calibration algorithm for generate to same bead shape to real database in process of generating bead. The best advantage of virtual welding training, it can be get the many data to training evaluation. In this paper, we were representation bead to similar shape from generated bead to Flux Cored Arc Welding. Therefore, we were reduce the gap to virtual welding training and real welding training. In addition, we were confirmed be able to maximize the performance of education from more effective evaluation system.

용접실습 교과목에 필수적인 기계제도 기초 이론 학습에 대한 증강현실 콘텐츠 시스템을 활용한 교육 방법 및 효과성

구창대,양형석,이동엽,Koo, Chang-Dae,Yang, Hyeong-Seok,Lee, Dong-Youp 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.4

Today, the development of digitized information media and info-communications are bringing many changes. Due to the development of IT thechnology, we can learn wherever, whenever, regardless of time and place. Machine drawing subject is a very important in mechanical engineering course, but it's studyed only basic theory in a short period, average 1~2weeks. So that, students think that the mechanical drawing is of minor importance. Such ideas make them difficult to impove sense of space in isometric drawing and drawing skill. Therefore, in this paper, augmented reality-based contents through the system, Mechanical Drawing of education to meet the effectiveness and satisfaction, student learning can be spontaneously it was construct self-system. And, Theoretical part of the Mechanical Drawing is proposed ensure more efficient and easier training. In this paper, we were test operation for user effectualness of proposed service at Korea Polytechnics Colleges a industrial facilities management in Daegu. Target user are 66 students, and The students were divided into experimental group and comparison group. Experimental results, experimental group was able to do systematically experience many Projection Drawing and Pictorial Drawing in short schooltime. And, The test operation results showed that have the possibility to meet education effectiveness and user satisfaction in this augmented reality-based contents system.

스플라인 알고리즘을 이용한 비드 가시화

구창대(Chang-Dae Koo),양형석(Hyeong-Seok Yang),김맹남(Maeng-Nam Kim) 대한용접·접합학회 2016 대한용접·접합학회지 Vol.34 No.1

In this research paper, suggest method of generate same bead as an actual measurement data in virtual welding conditions, exploit morphology information of the bead that acquired through robot welding. It has many multiple risk factors to Beginners welding training, by we make possible to train welding in virtual reality, we can reduce welding training risk and welding material to exploit bead visualization algorithm that we suggest so it will be expected to achieve educational, environmental and economical effect. The proposed method is acquire data to each case performing robot welding by set the voltage, current, working angle, process angle, speed and arc length of welding condition value. As Welding condition value is most important thing in decide bead form, we would selected one of baseline each item and then acquired metal followed another factors change. Welding type is FCAW, SMAW and TIG. When welding trainee perform the training, it’s difficult to save all of changed information into database likewise working angle, process angle, speed and arc length. So not saving data into database are applying the method to infer the form of bead using a neural network algorithm. The way of bead’s visualization is applying the spline algorithm. To accurately represent Morphological information of the bead, requires much of morphological information, so it can occur problem to save into database that is why we using the spline algorithm. By applying the spline algorithm, it can make simplified data and generate accurate bead shape. Through the research paper, the shape of bead generated by the virtual reality was able to improve the accuracy when compared using the form of bead generated by the robot welding to using the morphological information of the bead generated through the robot welding. By express the accurate shape of bead and so can reduce the difference of the actual welding training and virtual welding, it was confirmed that it can be performed safety and high effective virtual welding education.

국산 체외 충격파 쇄석기의 음향학적 특성 평가

최민주,이종수,김성삼,조성찬,양형석,손종수,천원기 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

In the study we measured and evaluated the acoustical property of a domestic spark gap type extracorporeal shock wave lithotripsy (ESWL). Altering the discharging medium between the electrodes of the shock wave generator (water, 1% an 10% NaCl electrolyte), we measured shock waveforms and sound pressure level (SPL). For the shock waves produced using the discharging medium, water, it was seen that the shock wave peak pressure went up to 70 MPa, and the SPL was in the range of 90 - 100 dB. As the concentration of NaCl increased in the electrolyte. the SPL did not change much and was shown to increase correlation with the discharging voltage. In the case of the discharging medium. 10% NaCl electrolyte, it was found that the shock amplitudes varied in a narrow range when being high in the concentration of NaCl and were large when being high in discharging voltages. While the stone fragmentation was in process, we measured the acoustic emission and compared their spectral properties.

음경, 음낭 및 하복부에 발생한 다발성 낭성 림프관종

김형곤,박정수,양형석,김제희,박원희 大韓泌尿器科學會 2002 Korean Journal of Urology Vol.43 No.11